Martin-Green, who plays Sasha on the AMC zombie apocalypse series, will play a lieutenant commander on the titular starship. This marks a major departure from past “Star Trek” series, which have typically focused on the captain of whatever vessel serves as the show’s setting. Martin-Green will continue to appear on “The Walking Dead” while starring on “Discovery.”

Representatives for Martin-Green and CBS declined TheWrap’s request for comment.

She is the latest addition to the quickly-expanding cast. Earlier this week, Chris Obi, Shazad Latif and Mary Chieffo joined the show as a trio of Klingon warriors. The series also recently cast Anthony Rapp, Doug Jones and Michelle Yeoh in key roles.

As originally planned, the premiere episode of “Discovery” will air on CBS, with all subsequent episodes available in the U.S. exclusively on CBS All Access. Each episode of the series will be available globally within 24 hours of its U.S. premiere, presented on Netflix in 188 countries and through Bell Media platforms in Canada.

“Star Trek: Discovery” is produced by CBS Television Studios in association with Alex Kurtzman’s Secret Hideout, Fuller’s Living Dead Guy Productions and Roddenberry Entertainment.